"Tsarnaev should not be heard to complain about the receipt of information that he himself has requested and that the government had no legal obligation to provide earlier (or at all)," prosecutors wrote.

Tsarnaev's lawyers argued in their motion filed on Tuesday that a September trial date would be more realistic given the "extraordinary complexity and international dimensions" of the case.

Two bombs at the finish line of the April 15, 2013 Boston Marathon killed three people and injured more than 260 others. Tsarnaev's older brother, Tamerlan, died in a police shootout days after the bombing.

The court filing submitted by U.S. Attorney Carmen Ortiz also dismissed concerns raised by the defense about the scope of witness and exhibit lists filed under seal last week. The lists named more than 700 potential law enforcement and civilian witnesses and 1,238 exhibits.

Most of the law enforcement witnesses were involved in the collection, photographing or chain of custody of evidence and some could be taken off the list, prosecutors said, if the defense agreed to accept their findings as fact.

The government also said it has made "a good-faith effort to identify each item on its exhibit list in an understandable manner and stood ready to help the defense identify any item on the list that they could not identify on their own," the filing said.

Prosecutors did concede that they inadvertently failed to email the defense an index of additional materials it provided Dec. 15-18, but noted it did so as soon as the defense asked for the index.

It was not immediately known when U.S. District Court Judge George O'Toole Jr. might rule on the motion to delay the trial. He also is considering a defense motion filed earlier in the week to move the trial out of Massachusetts.

This past September, O'Toole denied earlier motions to move the case or delay it to September 2015, though he did agree to a roughly two-month delay from the original Nov. 3 trial date.